Methods of making separable fastening fabrics



May 23, 1967 J. NAIMER 3,320,649 I METHODS OF MAKING SEPARA BLE FASTENING FABRICS Original Filed Oct. 23, 1962 2 Sheets-Sheet 1 dfwi ak 6'7 0 mes 5 y 3,1 1 J. NAIMER 3,320,649

METHODS OF MAKING SEPARABLE FASTENING FABRICS Original Filed Oct. 25, 1962 2 sheetssheet 2 IIIII WI "IIIIIIIIIIIIIIIIIIIIIL INVENTOR zleaz Ale/Mae BY d #6 Q xii-A.

United States Patent 3,320,649 METHODS OF MAKING SEPARABLE FASTENING FABRIQS Jack Naimer, 40 Inglewood Lane, Matawan, NJ. 07747 Continuation of application Ser. No. 349,509, Mar. 4, 1964, which is a division of application Ser. No. 232,410, Oct. 23, 1962, now Patent No. 3,138,841. This application Mar. 21, 1966, Ser. No. 538,469

6 Claims. (Cl. 2872) This is a continuation of my application Ser. No. 349,- 509, filed Mar. 4, 1964, now abandoned, which was a division of Ser. No. 232,410 filed Oct. 23, 1962, now Patent No. 3,138,841, granted June 30, 1964.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

This invention relates to methods of making fabrics having a pile structure for separably engaging hooked or looped pile fabrics.

In Patent 2,717,437 there is disclosed a pile fabric structure having cut loops to form hooks whereby a pair of such fabrics in face to face relation may be interengaged and then separated by peeling the fabrics apart. It was found that a substantial portion of the individual hook structure did not actually interengage other hook structures, thereby reducing the holding power of the engaged fabrics.

Accordingly, in Patent 3,009,235 it was proposed to augment the holding power of the engaged fabrics by providing one of the fabrics with hooks while the other had loops for engagement by the hooks.

However, it has been found that the extent of interengagement of hooked fabric with a looped fabric is largely dependent on the relative position and direction of each of the hooked elements in respect to the opposed looped elements and in many cases, large numbers of the hooked elements were not in engaged relation to the looped elements.

Accordingly, an object of this invention is to provide a method of making a pile fabric structure wherein the individual pile elements have a terminal structure which enables said pile elements to effectively engage an associated looped fabric in all directions, thereby increasing substantially the proportion of pile elements in effective engaged relation and thus increasing the resistance of the engaged fabrics to disengagement.

Another object of this invention is to provide improved methods for treating pile fabrics having thermoplastic monofilament pile elements to impart a particular tip structure thereto in an eflicient and economic manner.

Still another object of this invention is to provide improved methods for treating pile fabrics to impart booklike, engaging effects to the individual pile elements, said methods involving regulatory procedures for adjusting the holding power or resistance to separation of the finished fabric, to predetermined value.

Other objects of this invention are in part obvious and in part hereinafter pointed out.

In the drawing, FIG. 1 is a transverse sectional view of a pile fabric structure which is to be converted into a separable fastener fabric of the instant invention;

FIG. 2 is an enlarged vertical sectional view of a beaded single monofilament of the pile fabric of the instant invention;

FIG. 3 is a view similar to that of FIG. 2, showing an alternative form of such monofilament;

FIG. 4 is a vertical section showing one method of forming the fastener fabric of this invention;

FIG. 5 shows an alternative method for forming such fastener fabric;

FIG. 6 shows still another method for forming such fastener fabric; and

FIG. 7 is a transverse sectional view showing the face to face engagement of two mating pile fabrics.

Essentially, the fastener member of the instant invention comprises a pile fabric such as a velvet or the like, wherein the usual woven foundation warp and weft threads thereof include upstanding pile warp threads, usually formed by cutting the tops of the loops formed during the weaving operation, or by medially cutting a double plush fabric. The resultant pile elements, which are of a thermoplastic material such as polypropylene or polyethylene, have their outer, tip portions subject to heat which exceeds the flow point of the thermoplastic material. This may be accomplished by cutting the pile elements in a medial plane intermediate the two base fabrics with a heated member or it may be subsequently accomplished with a heating tool after the base fabrics have been separated by the cutting member.

As a result of such heating operation, the tips of the pile elements fuse and draw back to form a beadlike or mushroornlike terminal structure. As shown in FIG. 7, the tip configuration has been found to be highly effective in engaging the loops 8 of an opposed fabric 9, such as typically shown in Patent 3,009,235, since the engaging action of such tip configuration is effective in all directions, in contrast to the unidirectional effectiveness of known hook structures.

Thus, as shown in FIG. 1, fabric base 10 woven on the usual velvet loom or the like, comprises foundation warp threads 11, weft threads 12 and upstanding pile warp threads 13. The pile warp threads are of polypropylene or polyethylene monofilaments. The resultant pile fabric is processed so as to subject the original outer end portions 14 of each warp pile thread 13, shown in dotted lines in FIG. 2 to heat which exceeds the flow point of the plastic forming such elements.

The original outer end portions 14 will then fuse and draw back to form a beadlike or mushroornlike head generally indicated in full lines at 15. Such head 15 comprises a substantiall part spherical surface portion 16 having an annular skirt edge 17, and an annular, substantially planar under surface portion 18 which extends radially outward to edge 17.

The head 15 is formed upon a relatively moderate exposure of the tips 14 of pile warp threads 13 to the heat source, and with a monofilament cross sectional diameter X of about .008, the diameter Y of head 14 at edge 17 is about .016. Such a bead configuration would provide a reasonable resistance to separation of the fabric 10 from a looped fabric, as shown in FIG. 7.

Upon doubling the heat exposure of tips 14, the fusion effect is increased somewhat, and the diameter Y at the bead edge 17 would be about .022. By increasing the heat exposure by about 400% there is a further increase in the fusion of the piletip 14 to produce a head 20, as shown, in FIG. 3, wherein the substantially part spherical top surface 21 extends to a peripheral edge 22 and the annular undersurface portion 23 extends upwardly and outwardly to said edge 22 with an annular portion 24 of very limited radial extent joining the inner edge of undersurface portion 23 to monofilament portion 25.

In the case of head 20, as shown in FIG. 3, the diameter Y at edge 22 is about .032" compared to the transverse diameter of .008" for the monofilament portion 25. With such head 20, the holding power and resistance of a fastener fabric incorporating the same is substantially greater than that of beads 15 having lesser skirt edge di ameters.

With head 15, as shown in FIG. 2, having a skirt edge diameter of about .016", the thickness of the bead indicated at Z is about .012". For a bead having a skirt 3 edge diameter of .022, the thickness Z would be about .015" and with bead 20, thickness Z, is about .022".

It will be apparent, that upon suitable regulation of the extent of exposure of the pile tip portions 14, 14 to the heat source, the size and configuration of the resultant beads may be varied, and thereby the holding elfect of the fabric may be adjusted;

The beads 15, 20cm the monofilament tips of fabric .10 may beproduced by procedures shown in FIGS-4, 5,

6. Thus, as shown in FIG. 4, a source of radiant heat 39, such as one or more Nichrome Wires suitably energized, or one or more quartz lamps, is located adjacent a pile fabric 31' moving in a path, by means not shown, to locate the tip ends 32 of pile elements 33 in suitably spaced relation to radiant heat source 30. The rate of movement of fabric 31 is suitably controlled to obtain the desired heat exposure. Alternatively, the spacing of the heat source relative to the tip ends 32 or the intensity of the heat source may be varied to obtain the desired bead configuration 34.

As shown in FIG. 5, a double plush woven fabric 40 produced in a conventional manner and including as pile elements polypropylene monofilaments, is cut in a medial plane by a heated knife 41 traveling from edge to edge of the loom. Thus, with the knife 41 heated above the flow point of the monofilament plastic, not only is the double fabric 40 separated into separate pile fabrics 42, 43, but in addition, the tips of the pile elements 44 are fused to form the beads 45. Alternatively, a stationary heated Nichrome wire may be used which extends over the full Width of the loom to cut and bead the pile elements.

As shown in .FIG. 6, the cut pile fabric 50 having monofilament pile elements 51 of polypropylene is brought into contact with a heated platen 52 which under controlled temperature of about 360 F. and applied pressure will be effective in about 1.5 seconds to bead the ends of elements 51, as at 53.

Polypropylene, used in forming the pile elements of the fabric herein, has a melting point of the order of 290330 F. With such pile elements, a heat source in the form of a single quartz lamp having a surface temperature of 3,000 P. may be located at a distance of about 7%2" from the ends of such pile elements and with an exposure of /2 second, the ends of the pile elements will be converted into beads of suitable configuration, as described a'oove., v

The pile fabrics may also include pile warp threads of polyethylene, which have a melting point in the range of 225 to 280 F. With such thermoplastic monofilaments,

the heat source to which thepile element tips are exposed, 5

is suitably adjusted to produce the desired form of bead as shown in FIGS. 2 and 3.

As the embodiments of the invention herein disclosed may be changed without departing from the spirit of the invention, it is understood that all matter herein shown or described is to be deemed illustrative and not limiting except as set forth in the appended claims.

I claim:

1. A method of making a separable fastener from fabric having a plurality of pile elements made of thermoplastic material formed with upstanding terminal ends, including the steps of: heating said ends of the pile elements to a temperature exceeding the flow point of the thermoplastic material whereby said ends melt and enlarge; and maintaining said enlarged ends of the pile elements at said temperature for a formation period of predetermined duration during which the enlarged terminal ends drawback into a mushroom-shaped configuration having an upper, substantially spherical surface and an annular, non-spherical undersurface.

2. The method of claim 1 wherein said terminal ends are heated to said temperature by spacing thereof by a distance of approximately of an inch from a surface at approximately 3,000 F., said predetermined duration of said formation period being at least 0.5 second.

3. The method of claim 2 wherein said thermoplastic material is selected from the group consisting of polyethylene and polypropylene.

4. The method of claim 1 wherein said terminal ends are heated to said temperature by contact with 'a surface at approximately 360 F., said predetermined duration of the formation period being at least 1.5 seconds.

5. The method of claim'4 wherein said thermoplastic material is selected from the group consisting of polyethylene and polypropylene.

6. The method of c1aim.1 wherein said thermoplastic material is selected from the group consisting of polyethylene and polypropylene.

References Cited by the Examiner UNITED STATES PATENTS 1,785,937 12/1930 Curtis 26-2X 2,587,792 3/1952 Von Sivers. 2,628,412 3/1953 Vera 28-72 2,820,277 1/1958 Forster 26-2 2,866,255 12/1958 Keen 26-2X 3,050,070 8/1962 Sidelman 132 39 MERVIN STEIN, Primary Examiner.

L. K. RIMRODT, Assistant Examiner. 

1. A METHOD OF MAKING A SEPARABLE FASTENER FROM FABRIC HAVING A PLURALITY OF PILE ELEMENTS MADE OF THERMOPLASTIC MATERIAL FORMED WITH UPSTANDING TERMINAL ENDS, INCLUDING THE STEPS OF: HEATING SAID ENDS OF THE PILE ELEMENTS TO A TEMPERATURE EXCEEDING THE FLOW POINT OF THE THERMOPLASTIC MATERIAL WHEREBY SAID ENDS MELT AND ENLARGE; AND MAINTAINING SAID ENLARGED TERMINAL MENTS AT SAID TEMPERATURE FOR A FORMATIN PERIOD OF PERDETERMINED DURATION DURING WHICH THE ENLARGED TERMINAL ENDS DRAWBACK INTO A MUSHROOM-SHAPED CONFIGURATION HAVING AN UPPER, SUBSTANTIALLY SPHERICAL SURFACE AND AN ANNULAR, NON-SPHERICAL UNDERSURFACE. 